EVALUATION OF 2 COWSIDE TESTS FOR THE DETECTION OF SUBCLINICAL KETOSIS IN DAIRY-COWS

The goal of this study was to evaluate the sensitivy and specificity o f two cowside tests for subclinical ketosis in diary cows. The tests u tilize milk and urine samples, respectively. One hundred and eighty-fi ve cows, one to sixty days postpartum, were sampled for milk, urine, a nd blood. Subclinical ketosis was defined with serum beta-hydroxybutyr ate measurements. The sensitivity and the specificity of both tests at different beta-hydroxybutyrate levels were estimated. When subclinica l ketosis was defined at beta-hydroxybutyrate levels of 1.4 mmol/L and higher, the milk test had sensitivity of 90% and specificity of 96%. The urine test lacked specificity (values <67%), but sensitivity was 1 00% at beta-hydroxybutyrate levels of 1.4 mmol/L upward.Both the milk and urine test can be used to monitor subclinical ketosis in a herd. M ilk testing is preferred, because of the easy obtainability of milk co mbined with the overall better test characteristics.